Ideation
I was initially very intimidated by the idea of having to create a switch that didn’t use our hands (to turn on a switch, I’m assuming), especially after seeing the trash can example since it seemed like a relatively complicated example. However, I looked at a couple more examples from other students and it seemed like the idea itself had to be creative rather than the technical aspect being advanced. I almost immediately knew that I wanted to work with something that had to do with food utensils, then I thought of chopsticks. In Korea, people use chopsticks as their main utensil to eat but I always thought that it would act as an interesting pair of drumsticks.
Process
I replicated the switch circuit that we made in class then decided to use alligator tongles to collect the wires to one of each of the chopsticks. At first, I thought to use electricity-conducting tape, but then I had a hard time finding them in the lab so I decided to use the tongles. After I knew it worked by using one of the LED bulbs, I thought something more could be added to make the project more musical. This is when I decided to integrate a speaker into my circuit. I watched this tutorial to get a grasp on how to connect and play audio from Arduino then use the example code 02. Digital > toneMelody and integrated it into my switch code to play a sound when I’m hitting the chopsticks together.
Code Highlight / Obstacles
One part of my code that I’m particularly proud of is how I figured out the correct Arduino melody chords to play on the speaker. Unlike conventional musical notation, Arduino represents notes using predefined frequency values rather than standard sheet music notation. This means that converting a melody from traditional sheet music to Arduino code requires understanding how the notes map to Arduino’s tone() function.
To start, I searched for the chorus notes of We Will Rock You on the piano and found a beginner-friendly sheet music version. The melody consisted of the notes F, E, D, C, D, and D in the fourth octave. Since Arduino uses a different notation system, I used ChatGPT to convert these piano notes into corresponding Arduino frequency values.
After generating the initial translation, I decided that the melody sounded too low, so I asked ChatGPT to shift the notes up by one octave. This adjustment results in the notes F5, E5, D5, C5, D5, and D5, which gave the melody a brighter and more distinct sound when played through the speaker.
const int melody[] = {698, 659, 587, 523, 587, 587};
In addition, one part that I also struggled with was making sure that the notes incremented by 1 each time that the switch was turned on since in the loop it kept going around in the same-ish notes because I had initially put the noteIndex increment in the else statement. So I instead created a boolean variable that would be set to false and then set to true once I hit the chopsticks together for the first time. After that, there was an else statement that would check if first was true, and only then increment the noteIndex and set first back to false. This way, the note only advances once per button release, preventing the loop from rapidly cycling through all the notes while the button is held down.
if (switchPosition == HIGH) {
first = true;
digitalWrite(ledPin, HIGH);
tone(speakerPin, melody[noteIndex]);
} else {
digitalWrite(ledPin, LOW);
noTone(speakerPin);
if (first) {
noteIndex = (noteIndex + 1) % 6;
first = false;
}
}
Watch my live demo in class hehe 